The underwater glider can soar through the ocean without active propulsion, and it has become an effective tool for long-term ocean exploration due to its advantages, such as low energy consumption and high efficiency. In recent years, to improve the adaptability of underwater gliders under varying operation conditions, the deformable underwater glider has attracted widespread attention. This paper proposes a multi-objective optimization-based design method for a deformable underwater glider to improve its comprehensive performance. First, the configuration parameters of the deformable underwater glider are determined, including the morphing nose cone parameters (nose cone length and bending angle) as well as the deformable wing parameters (wing span and sweep angle). Based on the dynamic model and CFD simulations, the performance evaluation models of the deformable glider are established, considering energy consumption, voyage velocity and voyage range. Meanwhile, the effects of the morphing nose cone and deformable wing configuration on the hydrodynamic characteristics of the glider are analyzed. Then, the multi-objective optimization model for configuration parameters is established, and the non-dominated sorting genetic algorithm II (NSGA-II) is employed to obtain the Pareto optimal set. The results show that after optimization, the energy consumption, voyage velocity and voyage range of the deformable glider are all improved under the same operation conditions. The proposed research methods and findings provide new directions for the development of deformable underwater glider technology.